1. Field of the Invention
The present invention relates to an engaging post for a heat-dissipating device, and more particularly to an engaging post that may secure the heat-dissipating fan to an object in a convenient manner with a better securing effect.
2. Description of the Related Art
U.S. patent application Ser. No. 09/559,078 filed on Apr. 27, 2000 discloses positioning devices for a heat-generating element (e.g., a central processing unit) and a heat-dissipating device. The heat-dissipating device includes a base made of metal of excellent thermal conductivity and a cover plate to which a fan is mounted. The base has an underside in intimate contact with the central processing unit. The base includes a plurality of peripheral fins that define a central compartment for receiving the fan. The cover plate includes a plurality of posts each passing through a positioning hole defined in the circuit board and/or a positioning hole defined in the base, thereby securing the cover plate and the base to the circuit board and providing the required positioning effect. Each post includes a snap fastener on a lower distal end thereof, the snap fastener having a longitudinal slit to provide the snap fastener with required resiliency for compression and expansion in a radial direction when the snap fastener is passed through a corresponding positioning hole. Nevertheless, the snap fastener tends to have a resiliency fatigue or break by the root portion thereof due to repeated detachment and assembly.
It is an object of the present invention to provide an engaging post for a heat-dissipating device, wherein the engaging post can be assembled and detached in a convenient manner. In addition, the engaging post can be used for a long time while providing a reliable securing effect.
The present invention provides a positioning device for a heat-dissipating device. The positioning device includes a fixing plate to which a heat-generating element (e.g., a processing unit) is mounted. The positioning device further includes a cover plate having a plurality of engaging post extended therefrom. Each engaging post is extended through an associated positioning hole in the fixing plate. Each engaging post includes a conic engaging end with an enlarged annular shoulder that is passed through the associated positioning hole when attaching the cover plate to the fixing plate. The annular shoulder is compressed when it is passing through the associated positioning hole and then returns to its original shape after passing through the associated positioning hole so as to be retained to an underside of the fixing plate. In a preferred embodiment of the invention, the annular shoulder includes a longitudinal slot to allow deformation when it is passing through the associated positioning hole.
Other objects, specific advantages, and novel features of the invention will become more apparent from the following detailed description and preferable embodiments when taken in conjunction with the accompanying drawings.